Cellular polyurethane foams made by reacting an organic polyisocyanate with a polyether containing methyl glucoside in the presence of a blowing agent are known in the art. For example, Hostettler et al, U.S. Pat. No. 3,073,788, assigned to Union Carbide Corporation, discloses such cellular foams and their methods of preparation. The '788 patent teaches that the foams disclosed herein are capable of preparation without the application of external heat and have either high or low density by suitable modification, good resistance to solvents, and little tendency to support combustion.
Methyl glucoside is known in the art to provide polyurethane foams characterized by their ability to continue to swell and not shrink, even under severe heat aging conditions of 230.degree. F. Such a disclosure is found in a technical article by J. J. Cimerol and S. Fuzesi, "Methyl Glucoside Based Rigid Urethane Polyols and Foam," printed in Polyurethanes for Tomorrow, proceedings of the SPI 26th Annual Conference (1981).
Thermoplastic polyurethane elastomers based on poly(oxypropylene)-poly(oxyethylene)glycol wherein the oxyethylene content is at least 15 percent are disclosed in U.S. Pat. No. 3,983,094, assigned to Uniroyal, Inc., as being thermally stable for processing steps such as painting at temperatures as high as 250.degree. F. However, these elastomers are thermoplastic and would melt if exposed to such a high temperature for more than a very brief period of time. Moreover, these elastomers are frequently produced using an ethylene glycol or 1,4-butanediol chain extender and, since the ethylene glycol or 1,4-butanediol is generally not soluble in the reaction medium, separation of the reaction mixture occurs on standing.
Non-foam thermosetting polyurethanes such as elastomers capable of withstanding high temperatures of at least about 140.degree. F. or higher for at least twelve hours were not known prior to the invention herein, based upon the knowledge of the present inventors. Indeed, prior art polyurethane elastomers tend to exhibit thermal degradation at temperatures well under 140.degree. F in such a time interval.
The disadvantages associated with using polyurethane elastomers that tend to thermally degrade at temperatures of 140.degree. F. or lower are readily apparent. For example, when using such elastomers as a thermoconductivity barrier for aluminum window frames, such degradation conditions can cause the windows to fall out of their frames. On this basis, the discovery of new polyurethane elastomers resistant to high temperature thermal degradation would be highly desirable.